Frank



m0 Model.)

' F. W. ME'RRITT.

' ELECTRIC PUMP. I No. 510,921; Patented Dec. 19, 1893.

@l VU QMY/ UNITED STATES PATENT OFFICE.

FRANK. W. MERRITT, OF DULUTH, MINNESOTA, ASSIGNOR TO THE ELECTRIC MOTOR COMPANY, OF SAME PLACE.

ELECTRIC PUMP.

SPECIFICATION forming part of Letters Patent No. 510,921, dated December 19, 1893. Application tiled December 2, 1892. Serial No. 453,824. (No model.)

To all whom it may concern:

Be it known that I, FRANK. W. MERRITT, of Duluth, in the county of St. Louis and State of Minnesota, have invented certain new and useful Improvements in Controllers for Electrically-Actuated Pumps; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawing, and to the letters of reference marked thereon,which forms a part of this specification.

The main object of my invention is to antomatically control the operation of electrically operated pumps.

It consists essentially of the combination with a pump and electric motor arranged to actuate the same, of a controlling device arranged to stop the motor when the pressure produced by the pump rises above a certain point and to start the pump when the pressure falls below that point.

In the accompanying drawing, illustrating my invention, the controlling device is shown in detail, while the pump and motor are shown on a reduced scale, mainly in diagram.

A represents the pump cylinder, B the piston, O the piston rod, D a straight bar armaf, ture attached directly to the piston rod Oand provided in the direction of its length with a number of coils d d.

E is the commutator carried by the armature, and consisting of a series of insulated contact plates (2 6, arranged parallel with the axis of the motor.

F F are the brushes, arranged to bear upon the commutator plates and connected by suitable conductors with a source of electricity. The armature D is arranged to reciprocate in the field of one or more series of magnetsN S, arranged parallel with the axis of the armature and of alternately opposite polarity, as indicated by the reference letters.

G is a switch arranged to be operated by the movement of the armature to reverse the direction of the current at the end of each stroke of the armature, through the armature coils as shown, or through the field coils. The armature coils (Z d are severally con nected with the corresponding commutator plates 6, and the brushes E F'are set at adistance from each other corresponding approximately with the distance between the poles of adjacent field magnets. There area number of armature coils to each length of the armature, corresponding with the distance between adjacent field magnet poles.

Although I have shown and described my invention for the purpose of illustration in connection with a reciprocating pump and motor, the controlling device constituting the essential feature of my invention is applicable to various other forms of pumps and electric motors.

H represents a compressed air chamber or receiver connected with the pump. It connects through a pipe h h with one end of a cylinder I, constituting a part of the motor controlling device. J is a piston fitted and adapted to work in said cylinder. It is attached to a piston rod j, which is pivoted at j to a lever K, the pivot pin'being provided with a bushing of insulating material, whereby the piston rod J is insulated from said lever. The lever K is pivotedat k to an insulated base R, which carries the controlling device, and it is provided at the end opposite its pivot connection j with a contact piece L, pivoted thereto at Z. This contact piece is provided on one side with an insulated block or strip of insulating material Z. K is electrically connected with one of the conductors leading to the generator.

M is a lever pivoted at m to the base R and held normally by a spring Q against the stop m.

P is a spring connected with the contact piece L a little below its pivot connection Z, with lever K, and adj ustably attached at its opposite end by a screw and nut 10, to the base R. By means of this nut and screw the tension of said spring may be adjusted as desired. The lever M is electrically connected by a suitable conductor, with the motor.

A spring 0 is placed on the piston rod j between the piston and a perforated screw threaded plug 0, through which the piston rod passes, and by which the tension of said spring may be adjusted as desired.

The lever A section h of the pipe connecting the air receiver Hand cylinder I, may be made of rubber or other non-conducting material, but this is not necessary when the piston rod j is insulated from the lever K by a non-conducting connection.

The controlling device thus described op-' erates as follows: The tension of the springs O and P being adjusted to sustain a certain pressure per square inch upon the piston J, when the pressure produced by the pump in the receiver H rises above that point the piston will be moved to the right, carrying levers K and M into the positions indicated by dotted lines. The lever M being thus released by the contact piece L, is withdrawn by spring Q toits normal position against stop m, thereby breaking the .electrical connection between the generator and motor, and stopping the motor. As the pressure falls in the receiver H, the piston J will be moved to the left by the action of springs O and P, until the pressure reaches the predetermined point for which the controlling device is set. Thereupon the-spring P will cause the insulating strip Z to clear the end of the lever M, and will cause the contact piece L to engage therewith,.as shown in the drawings, thereby automatically establishing the electrical connection with the generator and motor, and starting the motor.

The pump will continue to operate until the pressure again rises above the point for which the controlling device is set, whereupon the circuit will be automatically broken by the controlling device hereinbefore explained, and the operation of the pump temporarily stopped until the pressure falls to the predetermined point.

Various changes in the details of construction and arrangement of the controlling device audits component parts may be made within the spirit of my invention.

I claim- .1. The combination with a pump, an air receiver connected therewith and an electric motor connected with and arranged to actuate the pump, of a controlling device connected with the air receiver and arranged to automatically break the circuit and stop the motor when the pressure rises above a certain predetermined point, and to automatically close the circuit when the pressure falls to that point, substantially as and for the purposes set forth.

2. The combination with a pump and electric motor connected therewith, ofa controlling device comprising a cylinder connected with the compressed air chamber of a pump,

a piston arranged to work in said cylinder, and a circuit maker and breaker connected with said piston and controlling the circuit between the generator and motor, substantially as and for the purposes set forth.

3. Thecombination with a pump and electric motor connected with and arranged to operate the same, of a circuit controlling desaid contacts being connected with the generator and the other with the mo:tor,substantially as and for the purposes set forth.

4. The combination with a pump and an electric motor connected with and arranged to operate said pump, of acontrolling device comprising a cylinder connected with said pump, a piston arranged to work within said cylinder, a lever connected with said piston and provided with a contact piece pivoted thereto and having an insulated section, a spring connected with said contact piece and acting thereon in opposition to said piston, means for adjusting the tension of said-spring, a lever arranged to engage with said contact piece in normal position, and with the insulated section in abnormal position, .and a spring connected with said lever and tending to restore it to normal position, the motor and generator being electrically connected with said con-tact piece and with said last mentioned lever, substantially as and for the purposes set forth.

In testimony that I claim the foregoing .as my own I affix my signatu rein presence of two witnesses.

' FRANK. W. MERRITT.

Witnesses: v CHAS. A. TOWNE, J. D. ELLIs. 

